Premature ventricular contractions (PVCs) are premature depolarizations that originate in the ventricle. PVCs can cause symptoms such as palpitations, chest pain and syncope. However, PVC is a ubiquitous heart rhythm, occurring both in healthy patients as well as those with underlying heart disease. PVC morphology (i.e., shape) depends on the ectopic ventricular pacer location that triggered the contraction and the depolarization route taken by the contraction. PVCs that originate at the same ectopic pacer location and depolarize via the same route are known as unifocal PVCs, while PVCs that originate from multiple ectopic pacer locations and/or take different depolarization routes are known as multifocal PVCs. The treatment for unifocal PVCs may be different than the treatment for multifocal PVCs.
However, because the number of PVCs occurring within a given day may number in the hundreds or thousands, it is currently not feasible for a technician to review the amount of data required to deduce whether the PVC is unifocal or multifocal. In addition, because the occurrence of PVCs does not typically cause great discomfort to a patient, the occurrences may go unreported. However, long-term PVC prevalence may either cause or be a leading indicator of more serious cardiac conditions. Therefore, it would be beneficial to not only detect and monitor the prevalence of PVC in a patient, but further determine the type/cause of the PVCs, such that appropriate treatment may be applied.